Apparatus for forming sheet metal material



Aug. 12, 1952 B. F. RAYNES APPARATUS FOR FORMING SHEET METAL. MATERIAL 3 Sheets-Sheet l 9 AN N Filed Dec. 16, 1947 27 IN! 'EV TOR.

- BURT F. RAYNES ATTORNEY B. F. RAYNES 2,606,516

APPARATUS FOR FORMING SHEET METAL MATERIAL Aug. 12, 1952 3 Sheets-Sheet 2 Filed Dec. 16, 1947 IN VEN TOR. BURT E RA Y/V E S A T TORNE Y Aug. 12, 1952 B. F. RAYNES 2,606,516

APPARATUS FOR FORMING SHEET METAL MATERIAL Filed Dec. 16, 1947 5 Sheets-Sheet 3 INVEN TOR. BURT F. RAY/V53 BMW A TTORNE Y Patented Aug. 12, 1952 MATERIAL APPARATUS FOR FORMING SHEET METAL Burt F. Raynes, San Diego, Calif., assignor, by

mesne assignments, to. Harbor Aircraft Corporation, a corporation of California Application December 16, 1947, Serial No. 791,962 1 4 Claims. I

My invention relates to apparatus for forming sheet metal material, particularly presses employing rubber and form dies for shaping sheet metal bands, strips or tubes in desired circular forms, contours and configurations; and its objects are to utilize the elastic properties of a mass of rubberlike material encased in a metallic cylinder in cooperation with a solid or collapsible former die for pressing out from sheet metal an annulus or prismatic shell of predetermined form and dimensions; to provide adequate pressure means for compressing the mass of rubberlike material so as to force the same laterally and outwardly against the configured walls of the die to impress and impact the sheet metal workpiece thereon and to cause it to assume the form of the die; to allow the workpiece so formed readly to be removed from the die, and an unformed workpiece readily to be installed to take the place thereof; to render the parts readily accessible for inspection, removal, replacement, renewal and repair, and generally to provide an apparatus which is economical of construction, efficient in action and of prolonged life and durability. These and other objects will appear from the drawing and as hereinafter more fully set forth and described.

Attention is hereby directed to the accompanying drawing, illustrating a preferred form of my invent-ion, in which similar numerals of designation refer to similar parts throughout the several views, and in which,

Figure l is a vertical section of my improved apparatus, including the punch member as adapted to be mounted upon the press ram of a conventional hydraulic or mechanical press, and including the collapsible die, located below in registration therewith, and showing the press open and the unformed work piece seated in the die and about to be operated upon;

Fig. 2 is a section similar to that shown in Fig. 1, showing the press closed, and the work piece formed;

Fig. 3 is an enlarged detail section of a portion of the collapsible die and adjacent parts, as shown in Fig. 1, just before beginning the actual operation upon the workpiece;

Fig. 4 is the same view in section as that shown in Fig. 3, showing partial collapse of the die and bending of the work piece;

Fig. 5 is also the same view as that of Fig. 3,

showing the operation completed and the work piece fully formed; I

Fig. 6 is an enlarged view in perspective of finished annular work piece shown in section in Fig. 5, a portion thereof being shown removed for better illustration;

Fig. 7 is an enlarged section of a modification of the view shown in Fig. 1, showing the parts adapted for the formation of an annular work piece of different formation from'that illustrated in Fig. 6, before the beginning of the operation;

Fig. 8 is the same viewers that shown in Fig. '7, except that the parts are shown in compressed relation and the operation completed;

Fig. 9 is an enlarged planlview of the bottom portion of the die, showing thearcuate ,slots therein and enlargements at. .the .ends thereof for attaching and removingjthesecuring bolts of the top portion ofthe die, and 3 Fig. 10 is a section on line IO-kl of. .F i. 9, showing the vertical configuration or forin .of one of said arcuate slots, and engagement-thereof with one of said securing bolts. I

Referring to the drawing, connected by any suitable means to the press ram ofa conventional hydraulic or mechanical press (not shown), is the metallic mounting plate 9, to which plate are rigidly secured the piston I0, preferably cylindrical in form as here shown and of hardened steel, and also the metallic stripper bolts l I; countersunk screws l2 serving firmly to attach the said piston to the central part of said plate, and the upper end portions of said bolts being in threaded engagement with openings formed in said plate near the edges thereof. Preferably the piston I0 is formed with the flat bottom l3, to which is cemented or otherwise secured the fiat top H of the elastic cylindrically shaped punch I5 downwardly depending therefrom; the peripheral wall ofsaid punch conforming to that of said pistonandbeing in linear extension thereof. This punch I5 is preferably of soft commercial rubber of approximately forty-five Shore hardness, but maybe of any rubberlike material suitable for the purposes herein set forth, and is preferably provided at the bottom with the narrowed extension I 6. Normally in sliding engagement with the walls of both said piston and punch is the inner wall of the sleeve ll, which is preferably of hardened steel, and serves as a lining for the tubular structure l8, preferably a hollow cylinder in form as here shown and made up of a tier of separable hollow blocks or sections i9, 20, 2| and 22; through each of which passes in openings provided therefor the shanks of the said stripper bolts ll. As shown, ,the openings 22a in the lower block 22, are each enlarged and counterbored at the bottom in order to receive and secure the heads I la of said bolts and to allow a limited vertical movement or play thereof. Also expansion helical springs 23, encompassing the upper part of the shanks of said bolts and separating the mounting plate 9 from the block l9, are provided normally to hold this plate and block apart in the relation shown in Fig. 1, when the press is in open position. All of the foregoing parts taken together comprise the punch assembly of my apparatus.

Afiixed to the bed 24 of the press is the mounting plate 25, upon which rests and to which is secured the body of the die 26, positioned to make accurate engagement with the bore of the'sleeve ll of the cylinder [8, when the same is forced downwardly by the ram of the press; the die 28 being centered in the desired position by means of locating dowel pin 21, passing through the.

plate 25 and engaging with the opening 28 in the bottom wall of the'die. As shown, the die 25 is composed of the top and bottom-separable portions 29 and 30, connected by the bolts 3|; the upper ends of which are in threaded engagement with the said top portion 29, and the shanks 3Ia of which bolts engage with and slide within the arcuate slots 33 in the said bottom portion 36; the heads 3Ib of said bolts engaging with and sliding within enlargements 32 formed in the lower part of said slots 33, and being sole1y removable therefrom through other enlargements 32a formedat the ends of said slots 33; and the connection of said bolts being such through the narrower portions of, said slots as to allow only a limited vertical separation or the two portions of the die for the purpose shortly to be described, but permitting complete separation of said portions upon twisting the upper portion of the die upon the lower so as to bring the heads Slb of the bolts in registration with enlargements 32a and to be easily removed therefrom. Within the annular stepped recess 34 of the portion 29 is seated and normally secured by set screws Eda. the retainer ring 35; and within adjacent walls of the two said portions of the die are formed recesses 35 and 31, positioned to engage with the central part of the workpiece 38. Also within the circular depression 39, formed in the, top of the wall of portion 30, is seated the disc it; countersunk screws 4| passing through openings provided therefor in both said disc and adjacent wall and entering the mounting plate 25 serving firmly to secure thereto this portion of the die. In Figs. 7 and 8, I have shown my invention adapted for impacting laterally to conform to the configuration of the surrounding wall forming the block of the die,.a workpiece #2 in the form of a truncated conical sheet metal shell. Here, as shown, the height of said workpiece is of much greater length than that of the one piece rin 38; but the construction and relation of the working parts of the die and operation of the 8, but also of other forms of sheet metal strips bent to form hollow cylindrical or oval shells, or other hollow prismatic forms, adapted to be inserted within and to be acted upon by a die conforming thereto. Also if desired, sheet metal tubing or cylindrical casings cut into suitable lengths could be used as workpieces.

In operating the form of apparatus shown in Figs. 1 to 6, inclusive, the following steps are to be employed: While the punch assembly of such apparatus is in the elevated open position shown in Fig. 1, the top portion 29 of the die 26 is twisted clockwise upon the bottom portion thereof so as to slide the heads 3!?) of the bolts 3| into the enlargements 32a, and then the said top portion is lifted out of engagement with said lower portion of said die, leaving freely exposed the upper surface thereof. Thereupon, the ring or endless workpiece 38 is seated in the retainer step 44 of the bottom portion of said die, adjacent to the recess 31, and then the heads 3Ib of the bolts 3| are made to re-engage with the enlargements 32a, and the shanks of said bolts are caused to move contra-clockwise in the arouate slots 33, and thereby again to secure together as shown in Fig. 1, the two portions of said die; the top edgegof the workpiece 38 engaging with the annular lip a of retainer ring 35 and with the peripheral wall of the top portion 29 of said die adjacent to the recess 36, at which time the workpiece is in positionto be operated upon.

Thereafter, the press ram is caused to descend carrying with it the punch member of the appa ratus, the relative position of the parts remaining unchanged, until the sleeve ll of the cylinder it engages and encompasses the entire die 26;

the bottom of said cylinder coming to rest upon the plate 25 on the bed 24, and the extension it of the punch being thrust downwardly into the hollow of the die. Then, upon the continuance of the downward push of said ram transmitted through the plate ii to the piston id, and acting against the springs 23, the said piston is forced downwardly within the sleeve ll caused to compress the rubberlike mass forming the body of the punch I5 and I6 first against the sides of said sleeve and top of the die 2%, and finally against the forming parts of said die and upper face of the disc 40. Thus as the result of such continued downward movement of the press ram, and awakened thrust of the piston it, the rubberlike mass upon compression will act in the same manner as any confined hydraulic fluid to close the parts of the die 26 and forcibly to impact and press said mass against the wall of said workpiece and to apply great lateral pressure thereto, forcing the central portion thereof to bend outwardly against the adjacent parts of the die and to be pressed into the recesses 35 and 37 and finally to assume the form shown in Fig. 6.

Three stages of the bending or formation of the workpiece are graphically shown in Figs. 3, 4 and 5. In Fig. 3 is shown the initial unbent condition of the workpiece just prior to being acted upon by the rubberlike mass of the punch 15 and I 6. In Fig. 4 is shown the die under moderate or low pressure exerted mainly upon the top thereof and the partial bending laterally of the workpiece through some outward pressure of said mass. In Fig. 5 is shown the parts of the die under high pressure, causing the collapse thereof, and the forcing of the entire workpiece against the face of the die and the formation of the completed workpiece shown in Fig. 6.

It also appears that there are two distinct phases of the movement of the press ram and associated parts as above set forth, first, the initial downward movement of the said ram carrying the punch assembly without change in the relation of any of its parts, and second, the continued movement of the press ram against the springs 23, causing the thrust downwardly of the piston [0 against the rubberlike mass of the punch and bringing about the enforced flowage of said mass against the workpiece to compress the same against the forming face of the die.

After the workpiece ha been so formed, the press ram is caused to move upwardly, carrying with it the said punch assembly and associated parts, separating the same from the die, and again assuming the relative position thereof shown in Fig. 1; but before the said assembly is allowed to ascend, the pressure of the plate 9 against the springs and the compression of the piston l9 and of the rubberlike punch must first be released, whereupon the said parts in said released relation are carried upwardly as shown, freeing the die so that the workpiece 38 can be removed. This removal is readily accomplished I by turning the top portion 29 clockwise to release the bolts 31 from the bottom portion 36, and lifting the upper out of and away from the lower; at which time the formed workpiece may easily be detached from the die, and replaced by another unformed workpiece.

Where in the claims, I use the word workpiece I desire to be understood as meaning not only an annulus of sheet metal, but also as an equivalent any form of enclosed or continuous metal shell capable of being pressed by or upon a die into desired contours or configurations.

My invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment, as above set forth, is therefore to be considered in all respects as illustrative and not restrictive, the scope of my invention being indicated by the appended claims rather than by the foregoing description, and all changes which may come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What I claim and desire to secure by Letters Patent is:

1. Press means adapted to deform a workpiece to a desired shape in a press having a reciprocating ram and a stationary platen under said ram comprising, in combination: a collapsible die mounted on said platen, said die comprising spaced apart top and bottom sections, said top section being supported by the upright workpiece positioned between the sections, and said top section having a central opening; a punch connected to said ram; said punch comprising a hollow member having a marginal wall adapted for sliding engagement with both sections of said die; and a flexible member formed of resilient rubber-like material slidable along said marginal wall and having at its lower end a depending extension adapted to pass through said central opening of said top die section, and which is pressed against the bottom section of said die by the ram with a pressure suflicient to expand said extension by an amount sufiicient to deform the workpiece to the desired shape.

2. Press means as claimed is claim 1, in which; the region of said flexible member surrounding the upper end of said extension is arranged to press against the top section of said die section to compress the workpiece.

3. Press means as claimed in claim 1, in which said flexible member is arranged to press the top die section into engagement with the bottom die section, the inner faces of said top and bottom die sections defining the desired shape into which the workpiece is deformed.

4. Press means as claimed in claim 1, in which; one of said die sections is provided with a plurality of spaced apart arcuate slots, each slot having an enlarged portion at one end thereof; a plurality of spaced apart guide bolts secured to the other die section, the heads of said bolts being adapted to pass through the enlarged ends of said slots and to engage the other die section upon rotation of one of the die sections.

BURT F. RAYNES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 160,967 Stetter Mar. 16, 1875 506,247 Moorfield Oct. 10, 1893 562,309 Leavenworth June 16, 1896 568,804 Parish Aug. 24, 1897 731,367 Huber June 16, 1903 977,639 Lachman Dec. 6, 1910 1,934,292 Barker Nov. 7, 1933 2,190,664 Guerin Feb. 20, 1940 2,377,664 Berger June 5, 1945 FOREIGN PATENTS Number Country Date 604,472 Great Britain July 5, 1948 

